Recent Advances on the Use of Surfactant Systems as Inhibitors of Corrosion on Metallic Surfaces

Dual Role of a Ricinoleic Acid Derivative in the Aqueous Synthesis of Silver Nanoparticles

“…This is also observed in Figures 1(a) and 1(b), where initial spectra from AgNPs produced with 1.0 mM SEAR already present a positive curvature, as opposed to those from 10.0 mM. These results may be reasoned by selecting the CMC as the parameter that divides the two behaviors: before the SEAR CMC of 9.2 mM [23], SEAR molecules are readily available in solution for the reduction of Ag + , leading to quick AgNPs nucleation. After the CMC, on the other hand, SEAR molecules incorporated into micelles must be liberated through disruption of the micelle structure in order to make -OH groups available for further reduction of Ag + .…”

“…It is also important to take into consideration that the concentration of the capping agent (in the present study a role also played by SEAR) profoundly impacts on size and shape of nanoparticles, especially if the surfactant forms micelles [33]. Thus, we have selected SEAR concentrations of 1.0 mM and 10.0 mM, which correspond to concentrations below and above the SEAR critical micelle concentration (CMC) [23], respectively, to evaluate their impact on the reduction of Ag + and posterior stabilization. Figures 1(a) and 1(b) show time-dependent UV-Vis spectra of solutions that resulted from the addition of SEAR to AgNO 3 at room temperature and pH 13.…”

“…Originally used as a laxative folk medicament, castor oil is nowadays employed predominantly in cosmetic industries as a cream base in formulations of skin moisturizers [22]. It is primarily constituted of ricinoleic acid (approximately 90%), which can then be transformed into sodium ricinoleate via alkaline hydrolysis [23]. Teomim et al [24] hypothesized the use of ricinoleatebased polymers as drug carriers due to their lack of toxicity when tested in rats.…”

Cleaning Ability of Mixed Solutions of Sulfonated Fatty Acid Methyl Esters

“…a, b. This is not surprising, because the average thickness and morphology of the adsorbed surfactant (admicelles) on the solid surface are expected to essentially depend on surfactant concentration (De Oliveira Wanderley Neto et al, ; Zhang and Somasundaran, ).…”

“…This fact implies that the formation of surfactant adsorption bilayers or admicelles on the solid surface affect the detachment of oil drops. The morphology of the admicellar layer seems to be very specific and dependent on the kind of solid surface and surfactant type (Atkin et al, ; De Oliveira Wanderley Neto et al, ; Wangchareansak et al, ; Zhang and Somasundaran, ). We could hypothesize that admicelles of appropriate morphology can penetrate in the wedge‐shaped region near the three‐phase contact line and can act as “molecular jacks” that promote the full detachment of the oil drops from the substrate.…”